Circuit arrangement for weapons used in arming airplanes, particularly turret guns

ABSTRACT

The circuit arrangement is for loading electrically ignitable cartridges for airplane weapons and utilizes electronic components which are stable in a defined state, assume a metastable state, for the duration of a holding time, responsive to a triggering pulse, and flip back into the stable state at the expiration of the holding time, a typical such component being a monoflop (monostable multivibrator). When a cartridge ignition circuit is interrupted, with the weapon remaining inactive despite actuation of a firing button, a slow-pickup relay attracts, after a predetermined time, to close a relay contact which supplies a triggering pulse to a first monoflop which, in turn, generates an output pulse of defined duration. This pulse arrives through a first gate at a second monoflop and from the second monoflop to an output amplifier in which the pulse is amplified to the magnitude required to ignite a loaded cartridge. When a firing relay, included in the ignition circuit, is not activated, a flip-flop which is switched by a &#39;&#39;&#39;&#39;hand loading&#39;&#39;&#39;&#39; key supplies the pulse through a second gate to the second monoflop to trigger the latter. The second gate, conjointly with an inverter, prevents hand loading with the firing relay activated. A third gate and another inverter, in combination with filters in the output amplifier, prevent transmission of error pulses when a source of electric potential is connected to the circuit. Preferably, the slow pickup relay is activated after a time of about 300 m sec., and the first monoflop has a holding time of about 200 m sec.

United States Patent (191 Vorgrimler et al.

1 CIRCUIT ARRANGEMENT FOR WEAPONS USED IN ARMING AIRPLANES, PARTICULARLY TURRET GUNS [75] Inventors: Ludwig Vorgrimler, Oberndorf (Neckar); Klaus Vorgrimler, Grunwettersbach; Franz Stritt, St. Blasien, all of Germany [73] Assignee: Industrie-Werke Karlsruhe Augsburg, Germany [22] Filed: June I, 1973 [21] Appl No.: 366,163

[30] Foreign Application Priority Data June 2, 1972 Germany 1. 2226760 [52] U.S. Cl 89/1 K; 89/135 [51] Int. Cl F4ld 11/00 [58] Field of Search 89/1 K, 28, 135

[56] References Cited UNITED STATES PATENTS 3,103,851 9/1963 Rosenblum et all 89/1 K 3,440,926 4/1969 Gura et al 89/135 Primary ExaminerStephen C. Bentley Attorney, Agent, or FirmMcGlew and Tuttle [57] ABSTRACT The circuit arrangement is for loading electrically ig- MIME RTE)? June 10, 1975 nitable cartridges for airplane weapons and utilizes electronic components which are stable in a defined state, assume a metastable state, for the duration of a holding time, responsive to a triggering pulse, and flip back into the stable state at the expiration of the holding time, a typical such component being a monoflop (monostable multivibrator). When a cartridge ignition circuit is interrupted, with the weapon remaining inactive despite actuation of a firing button, a slow-pickup relay attracts, after a predetermined time, to close a relay contact which supplies a triggering pulse to a first monoflop which, in turn, generates an output pulse of defined duration. This pulse arrives through a first gate at a second monofiop and from the second monoflop to an output amplifier in which the pulse is amplified to the magnitude required to ignite a loaded cartridge. When a firing relay, included in the ignition circuit, is not activated, a flip-flop which is switched by a hand loading key supplies the pulse through a second gate to the second monoflop to trigger the latter. The second gate, conjointly with an inverter, prevents hand loading with the firing relay activated. A third gate and another inverter, in combination with filters in the output amplifier, prevent transmission of error pulses when a source of electric potential is connected to the circuit. Preferably, the slow pickup relay is activated after a time of about 300 m sec., and the first monoflop has a holding time of about 200 m sec.

Of? GATE FILTER TERM/NA L FILTER AMPL/F/ER PATENTEDJUH 10 ms 200m sec CHATTER/N6 Zmsec APPIOX.

45$UME came T- eam Y4 SL 014/ ACT/N6 RELAY man/0am MONO/FLOP CIRCUIT ARRANGEMENT FOR WEAPONS USED IN ARMING AIRPLANES. PARTICULARLY TURRET GUNS FIELD AND BACKGROUND OF THE INVENTION This invention relates to a circuit arrangement for loading electrically ignitable cartridges into weapons used to arm airplanes, such as turret guns, by using electronic components which are stable in a defined state, assume a metastable state responsive to a triggering pulse and for the duration of a predetermined holding time, and then flip back into the stable state at the expiration of the holding time, such electronic components comprising, for example, monoflops (monostable multivibrator).

Control devices of this type, which assure only the possibility of a single loading of the wepon, can be built and used without complications. However, if the safety of the weapon is to be increased, with the same probability of misfiring of the cartridges, an arrangement for multiple loading is required. When using conventional relay circuits, this presents difficulties. particularly because the rate of operation of the loading mechanisms differs considerably from the firing rate of the weapon, for reasons of cost and weight.

In a known weapon. the firing rate is about 33.3 msec. [,800 rounds/min. while the considerably lighter loading device can achieve a firing rate of 7.5 msec. or 8,000 loadings/min. This requires. however. control of the loading device with pulses of defined duration in order to eliminate the risk of double loadings. With pulses of this time order, however, the limit of the applicability of relays has probably been reached. Beacuse of unavoidable relay chatter, contact wear, and other concept related attraction and dropping, delays having pulse times of the order of about 2 msec can no longer be effected, with sufficient reproducibility, by using ordinary relays.

It is already known to effect control of the ignition current, for electrically ignited rapid fire wepons, in such a manner that the ignition current is supplied through a firing knob and a contactcontrolled by the operation of the weapon, for example, a breech block contact, to the electric percussion cap and through an insulating firing pin. The shot develops in the same manner as in conventional mechanical ignition. The gas pressure, generated during the firing, actuates additionally, in gas pressure loaders, a mechanism which assures the loading of another cartridge. When the breech block is again in the front position in such an arrangement, the ignition circuit is closed automatically so that the weapon continues to fire.

In weapons designed for use on board airplanes, such an arrangement makes no sense because the weapon would become completely inoperative in case ofa misfire. For these and other reasons, there are used loading mechanisms which work on a pyrotechnic basis in a manner such that, when an ignition pulse fails. to appear, or it interrupted after a certain time. such as 0.3 sec., at time element responds and releases the ignition current for an electrically ignited loading cartridge. Such a loading cartridge effects both the ejection of the defective cartridge and the feeding of another and flawless cartridge, so that the weapon again becomes operable.

SUMMARY OF THE INVENTION Because of the inconveniences and disadvantages described above. the object of the invention is to improve the presently known circuit arrangements by using particularly electronic components which are stable in a defined state, assume a metastable state responsive to a triggering pulse and for the duration of a holding time, and flip back into the stable state after expiration of the holding time. Typical examples of such electronic components are monostable vibrators, hereinafter referred to as monoflops.

In accordance with the present invention, the problem is solved in the following manner. When the cur rent serving to ignite the cartridge is interrupted, that is, when the weapon remains inactive despite the fact that the trigger has been pulled, a slow pickup relay is activated after a predetermined time interval, and closes a contact which supplies a triggering pulse to a first monoflop which generates an output pulse of a defined duration. This output pulse is supplied through a first OR gate to a second monoflop and from the second monoflop to an output or terminal amplifier in which the pulse is amplified to the magnitude required to ignite the cartridge. In the invention arrangemeent, when the firing relay is not activated a flip flop, switched by a hand loading" key, supplies a pulse through a second gate and the first OR gate to the second monoflop so that the latter is triggered and both monoflops conjointly prevent hand loading with the firing relay activated. Another switching means is provided and, together with known filters arranged in the output amplifier, prevents a wrong output pulse when a source of electric potential is connected to the circuit.

In a logical embodiment of the present invention, additional features are provided so that the slow pickup relay is activated after a time lapse of about 300 msec., and the first monoflop has a holding time of about 200 msec.

The present invention is further supplemented and improved by another feature in accordance with which the switching means preventing a wrong impulse, together with the filters arranged in the output amplifier, when a source of electric potential is connected to the circuit, is in the form of an additional gate including an inverter.

The present invention results in a number of marked advantages. Apart from the fact that the known circuit arrangements can be easily supplemented by using the features of the present invention, the circuit arrangement embodying the present invention opens up, additionally, the possibility of multiple loading and thus assures a far greater safety of the weapon provided with the invention circuit. By using modern electronic switching means, as are available in the form of known flip-flops and monoflops, the limits of conventional relays, with relatively slow switching times, are exceeded. In addition, by using the known flip-flop and monoflop elements, contact chatter, contact wear, etc., are avoided.

An object of the invention is to keep the rate of operation ofa loading mechanism indenpendent of the rate of operation of the associated weapon.

Another object of the invention is to provide an improvement in known circuit arrangements for loading and firing weapons designed for use on airplanes. particularly turret guns.

A further object of the invention is to provide an improved circuit arrangement of the type mentioned and which avoids the disadvantages of conventional relays.

For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings:

FIG. 1 is a circuit diagram ofa conventional weapon loading device as supplemented by a circuit arrangement embodying the invention as included in the area outlined by chain lines; and

FIG. 2 is a graphical illustration of the timedependent behavior of a slow pickup relay as well as the time-dependent behavior of two monoflops.

DESCRIPTION OF THE PREFERRED EMBODIMENT As the circuit shown in FIG. 1, except for the part enclosed in broken lines. corresponds to a conventional design. it will not be described in detail but the descrip tion will be limited to the essential components. However, that portion of the circuit outlined in broken lines. as illustrated in FIG. 1, will be described in detail hereinafter. Referring to FIG. 1, a source of electric potential. preferably a 24v source. is connected to the input terminals 1 which are succeeded by a main switch 2. A firing contact or trigger is illustrated at 3 and a Slow acting relay, such as a slow pickup relay, is illus trated at 4. The firing relay controlled by trigger 3 is indicated at 5, and 21 rounds counter is indicated at 6. The

electronic loading mechanism, forming the subject matter of the present invention. is generally indicated at 7.

The conventional circuit further includes a breech block contact 8, a barrel contact 9 and a counting contact 10. A loading cartridge 11 is provided to load cartridges 12 into the weapon, and a hand loading control I3 is further provided. An ohmmeter is indicated at 14 and a three step-switch is indicated at 15. A rate of fire switch 16 is provided to control the firing rate. A loading switch 17 is in circuit with slow acting relay 4, and filter sections. each comprising a resistor and capacitor in parallel. constituting a typical R-C filter. are indicated at [8 and 19. The terminals 20, associated with the firing button 3. are provided for connection of a remote control. and a rate of fire meter may be connected to the terminals 21 associated with the rounds counter 6. Various connecting plugs are indicated generally at 22, with protective resistors being indicated at 23 and 24. Relay 4 controls a contact 25.

When the current igniting a cartridge 12 is interrupted. that is. when the weapon remains inactive despite actuation of firing contact 3, slow acting relay 4 is activated after about msec. and triggers. through contact 25, the first monoflop MP] of the electronic loading system 7. The output pulse generated by monoflop MFI is supplied through an OR gate G3 to a second monoflop MF2, which latter provides an output pulse of about 2 msec. duration. The output pulse of monoflop MF2 is supplied to output amplifier EV where it is amplified to the magnitude required for igniting cartridge ll. Monoflop MFI has a holding time of 200 msec. and. in this time. the chatter of the contacts of slow acting relay 4 cannot affect the loading process.

With firing relay 5 not activated the output pulse of a flip-flop FFI, switched by the hand loading key 13, can arrive. through gate G2 and gate G3, at monoflop MF2 so that the latter is likewise triggered. Gate G2, with inverter G1. prevents hand loading with firing relay 5 activated. It will be noted that a contact of firing relay 5 is connected through inverter G1 to gate G2, and that monoflop MF2 is connected to amplifier EV through gate G4 and inverter GS. Gate G4 and inverter G5, in cooperation with known filters which have not been shown and which are arranged in output amplifier EV. prevent an error pulse or wrong pulse when the source of electric potential is connected to input terminals l, or when RF influences occur due to contact chattering of one of the external contacts or relay contacts.

As stated, FIG. 2 graphically illustrates the timedependent operation of slow-acting relay 4, in hand loading by means of firing contact 13. as well as the corresponding time-dependent operation of monoflops MFl and MF2. In FIG. 2. it is assumed that firing relay 5 is activated and gate G2 closed. The area .t denotes the activation of slow-acting relay 4 300 msec. after the last interruption of the ignition current, and .rx denotes the activation of relay 4 after the loading and the first interruption of the ignition current. The areas and .\'.r symbolize the chatter of the contacts. The delay time of 300 msec. provided for relay 4 is an empirical value. After such a time. ignition of the cartridge is practically impossible.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application ofthe principles of the invention. it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

I. In a circuit arrangement for loading electrically ignitable cartridges for weapons. particularly turret guns. destined for arming airplanes. and utilizing electronic components which are stable in a defined state, assume a metastable state, for the duration of a holding time. responsive to a triggering pulse. and flip back into the stable state at the expiration of the holding time. the improvement comprising. in combination, input terminals for connection to a source of electric potential; firing means actuable to establish a cartridge ignition circuit connected to said input terminals; a slow-acting relay energized from said source upon establishment of said ignition circuit and, after a predetermined time following interruption of the ignition circuit. with the weapon remaining inactive despite actuation of said firing means. closing a rely contact; a first said electronic component triggered. responsivie to closure of said relay contact. to generate an output pulse of defined duration; a second said electronic component; a first gate connecting said first said electronic component to said second said electronic component and triggered conductive by said output pulse to supply said output pulse to said second said electronic component; and an amplifier connected to the output of said second said electronic component and amplifying said pulse to the magnitude required for ignition of a loaded cartridge; said electronic components being monoflops.

2. In a circuit arrangement, the improvement claimed in claim 1, in which said firing means includes a firing contact and a firing relay energized responsive to closure of said firing contact; a flip-flop having an output connected to the input of said second monoflop; and a hand loading switch operable, when said firing relay is not energized, to switch said flip-flop to supply an output pulse to said second monoflop to trigger said second monoflop to supply an output pulse to said amplifier.

3. In a circuit arrangement, the improvement claimed in claim 2, including gate means connecting said firing relay and said flip-flop to said first gate and operable, in conjunction with said first and second monoflops, when said firing relay is not energized. to prevent hand loading by operation of said hand loading key.

4. In a circuit arrangement, the improvement claimed in claim 3, including switching means connected between said second monoflop and said amplifier and including filters arranged in said amplifier, operable to prevent error pulses when a source of electric potential is connected to said input terminals.

5. In a circuit arrangement, the improvement claimed in claim 4, in which said predetermined time of operation of said slow acting relay is of the order of 300 msec.

6. In a circuit arrangement, the improvement claimed in claim 4, in which the holding time of said first monoflop is of the order of 200 msec.

7. In a circuit arrangement, the improvement claimed in claim 4, in which said switching means comprises an additional gate.

8. In a circuit arrangement, the improvement claimed in claim 4, in which said gate means comprises a second gate connecting said flip-flop to said first gate; and a third gate connecting said firing relay to said second gate.

9. In a circuit arrangement, the improvement claimed in claim 4, in which the output pulse supplied by second monoflop to said amplifier has a duration of the order of 2 msec. 

1. In a circuit arrangement for loading electrically ignitable cartridges for weapons, particularly turret guns, destined for arming airplanes, and utilizing electronic components which are stable in a defined state, assume a metastable state, for the duration of a holding time, responsive to a triggering pulse, and flip back into the stable state at the expiration of the holding time, the improvement comprising, in combination, input terminals for connection to a source of electric potential; firing means actuable to establish a cartridge ignition circuit connected to said input terminals; a slow-acting relay energized from said source upon establishment of said ignition circuit and, after a predetermined time following interruption of the ignition circuit, with the weapon remaining inactive despite actuation of said firing means, closing a rely contact; a first said electronic component triggered, responsivie to closure of said relay contact, to generate an output pulse of defined duration; a second said electronic component; a first gate connecting said first said electronic component to said second said electronic component and triggered conductive by said output pulse to supply said output pulse to said second said electronic component; and an amplifier connected to the output of said second said electronic component and amplifying said pulse to the magnitude required for ignition of a loaded cartridge; said electronic components being monoflops.
 2. In a circuit arrangement, the improvement claimed in claim 1, in which said firing means includes a firing contact and a firing relay energized responsive to closure of said firing contact; a flip-flop having an output connected to the input of said second monoflop; and a hand loading switch operable, when said firing relay is not energized, to switch said flip-flop to supply an output pulse to said second monoflop to trigger said second monoflop to supply an output pulse to said amplifier.
 3. IN a circuit arrangement, the improvement claimed in claim 2, including gate means connecting said firing relay and said flip-flop to said first gate and operable, in conjunction with said first and second monoflops, when said firing relay is not energized, to prevent hand loading by operation of said hand loading key.
 4. In a circuit arrangement, the improvement claimed in claim 3, including switching means connected between said second monoflop and said amplifier and including filters arranged in said amplifier, operable to prevent error pulses when a source of electric potential is connected to said input terminals.
 5. In a circuit arrangement, the improvement claimed in claim 4, in which said predetermined time of operation of said slow acting relay is of the order of 300 msec.
 6. In a circuit arrangement, the improvement claimed in claim 4, in which the holding time of said first monoflop is of the order of 200 msec.
 7. In a circuit arrangement, the improvement claimed in claim 4, in which said switching means comprises an additional gate.
 8. In a circuit arrangement, the improvement claimed in claim 4, in which said gate means comprises a second gate connecting said flip-flop to said first gate; and a third gate connecting said firing relay to said second gate.
 9. In a circuit arrangement, the improvement claimed in claim 4, in which the output pulse supplied by second monoflop to said amplifier has a duration of the order of 2 msec. 